ARM: dts: am4372: Reserve pm code and data regions in ocmcram sram node

Add a 'pm_sram_code' reserved region to the ocmcram node to be exposed
by the mmio-sram driver as a pool but also mark it protect-exec so that
it can run code copied to it using sram_exec_copy.

Add another 'pm_sram_data' reserved region to the ocmcram node to act as
the data space for any code running from the 'pm_sram_code' region that
is exposed as a regular pool.
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am4372.dtsi

@@ -1141,6 +1141,21 @@ rfbi: rfbi@4832a800 {
 		ocmcram: ocmcram@40300000 {
 			compatible = "mmio-sram";
 			reg = <0x40300000 0x40000>; /* 256k */
+			ranges = <0x0 0x40300000 0x40000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			pm_sram_code: pm-sram-code@0 {
+				compatible = "ti,sram";
+				reg = <0x0 0x1000>;
+				protect-exec;
+			};
+
+			pm_sram_data: pm-sram-data@1000 {
+				compatible = "ti,sram";
+				reg = <0x1000 0x1000>;
+				pool;
+			};
 		};
 
 		dcan0: can@481cc000 {